Monday, December 5, 2011

Divisibility Rule For 9

Rule for 9 - The sum of the digits is divisible by 9.

1) You have a number.
eg. 1897236

2) You add them all together.

eg.















3) If you don't know if 36 is divisible by 9 then you take 36 and add them to make 3+6.


eg.












4) Now is 9 divisible by 9? Yes.

S0 1897236 is divisible by 9.

Now let's do another one.

37836547

Now use the steps.

So first you add them all together.

3+7+8+3+6+5+4+7=43

Now if you don't know if 43 is divisible by 9 then you add them together again.

4+3=7

7 is not divisible by 9. So 37836547 is not divisible by 9.

If you are still having trouble then here is a link that might help you.

If this link doesn't help you then try this video that might work better.



Hope this helped you if you were still having trouble finding out if a number is divisible by 9.

1 comment:

  1. Really good!!!! Nice explanation of divisibility rule for 9. what I really really liked was that you added a link and a video. I'm sure that this will help many people. Just one suggestion is that I think you shouldn't do so much of the colouring of the words, I like that its colourful but some words don't need to be coloured. Overall this was very good! Good job Jessica keep up the good work.

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